MSA  Vol.8 No.2 , February 2017
Porosity Effects on Interlaminar Fracture Behavior in Carbon Fiber-Reinforced Polymer Composites
Abstract: Fiber-reinforced polymer composite materials have become materials of choice for manufacturing application due to their high specific stiffness, strength and fatigue life, low density and thermal expansion coefficient. However, there are some types of defects such as porosity that form during the manufacturing processes of composites and alter their mechanical behavior and material properties. In his study, hand lay-up was conducted to fabricate samples of carbon fiber-reinforced polymer composites with three different vacuum levels in order to vary porosity content. Nondestructive evaluation, destructive techniques and mechanical testing were conducted. Nondestructive evaluation results showed the trend in percentages of porosity through-thickness. Serial sectioning images revealed significant details about the composite’s internal structure such as the volume, morphology and distribution of porosity. Mechanical testing results showed that porosity led to a decrease in both Mode I static interlaminar fracture toughness and Mode I cyclic strain energy release rate fatigue life. The fractographic micrographs showed that porosity content increased as the vacuum decreased, and it drew a relationship between fracture mechanisms and mechanical properties of the composite under different modes of loading as a result of the porosity effects. Finally, in order to accurately quantify porosity percentages included in the samples of different vacuum levels, a comparison was made between the parameters and percentages resulted from the nondestructive evaluation and mechanical testing and the features resulted from fractography and serial sectioning.
Cite this paper: Hakim, I. , Donaldson, S. , Meyendorf, N. , Browning, C. , (2017) Porosity Effects on Interlaminar Fracture Behavior in Carbon Fiber-Reinforced Polymer Composites. Materials Sciences and Applications, 8, 170-187. doi: 10.4236/msa.2017.82011.

[1]   Burton, S., Jenkins, N., Sharpe, D. and Bossanyi, E. (2011) Wind Energy Handbook. 2nd Edition, Wiley.

[2]   Bhat, M.R., Binoy, M.P., Surya, N.M., Murthy, C.R.L. and Engelbart, R.W. (2012) Non-Destructive Evaluation of Porosity and Its Effect on Mechanical Properties of Carbon Fiber Reinforced Polymer Composite Materials. Review of Progress in Quantitative Nondestructive Evaluation AIP Conferences Proceedings, 1430, 1080-1087.

[3]   Abdelal, N. and Donaldson, S. (2013) The Effects of Voids on Delamination Behavior under Static and Cyclic Mode I and Mode II’ 28 Technical Conference.

[4]   Olivier, P., Cottu, J.P. and Ferret, B. (1995) Effects of Cure Cycle Pressure and Voids on Some Mechanical Properties of Carbon/Epoxy Laminates. Composites, 26, 509.

[5]   ASTM Standard D5528 (2013) Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-Reinforced polymer Matrix Composites. Am Soe Testing and Materials, West Conshohocken.

[6]   ASTM Standard D6115 (2011) Mode I Fatigue Delamination Growth Onset of Unidirectional Fiber-Reinforced Polymer Matrix Composites. Am. Soc. Testing and Materials, West Conshohocken.

[7]   Hakim, I., May, D., Abo Ras, M., Meyendorf, N. and Donaldson, S. (2016) Quantifying Voids Effecting Delamination in Carbon/Epoxy Composites: Static and Fatigue Fracture Behavior. Smart and Nondestructive Evaluation for Energy Systems, Proceedings of SPIE, Las Vegas, Vol. 9806, 98060H-1.

[8]   Hakim, I., et al. (2016) The Effect of Manufacturing Conditions on Discontinuity Population and Fatigue Behavior in Carbon/Epoxy Composites. In Press in Conference of 43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, Atlanta.

[9]   Whitney, J.M., Browning, C.E. and Hoogsteden, W. (1982) A Double Cantilever Beam Test for Characterizing Mode I Delamination of Composite Materials. Journal of Reinforced Plastic and Composites.

[10]   Abdelal, N. (2013) Effect of Voids on Delamination Behavior under Static and Fatigue Mode I and II. Ph.D. Dissertation, University of Dayton, Dayton.